We have talked about the impersonal form of verbs in previous lessons. There's a great example in Marika's video about the entrance to her apartment. Note that she uses the plural form of the verb because the objects, giacche, giubbotti, cappotti (jackets, windbreakers, coats) are plural.

Nel inverno, si usano giacche, giubbotti, cappotti. Ma dove si mettono, una volta che si tolgono? And so we use jackets, windbreakers, coats. But where do we put them once we take them off?Caption 41, Marika spiega: L'ingresso di casa